It's not exactly clear how the wheat gluten, which never gets fully digested in anyone, enters the lining of the small intestine, provoking the reaction. It may occur when someone has a gastrointestinal infection; GI infections have been found to increase risk of the development of celiac disease in children. (Breastfeeding, however, has been found to protect children from celiac disease.) Once the immune system reacts to the gluten in the gut lining, it produces antibodies that mistakenly attack the lining of the small intestines, contributing to inflammation and the wearing away of the villi.
Not everyone who reacts to wheat has celiac disease, however. People with irritable bowel syndrome, who may have trouble tolerating a lot of grains, may have similar symptoms. And celiac disease should not be confused with a wheat allergy, which will produce allergic reactions that can range from hives and a rash to life-threatening anaphylactic shock.
When Should You Suspect Celiac Disease?
In adults and children, the villi damage caused by celiac disease can lead to symptoms such as abdominal pain, diarrhea, pale, foul-smelling stool, weight loss and weakness. Some people may develop an itchy, blistering rash called dermatitis herpetiformis. And irritability and depression may be seen in people with celiac disease. One reason the celiac disease diagnosis is challenging, however, is that the vague GI symptoms can also be caused by a number of other intestinal conditions, including irritable bowel syndrome, gastric ulcers and Crohn's disease.